In a silver halide color photographic material a color image is formed when the element is exposed to light and then subjected to color development. The color development results in imagewise reduction of silver halide and production of oxidized primary amine developer. The oxidized primary amine developing agent subsequently reacts with one or more incorporated dye-forming couplers to form dye in an imagewise fashion.
Many photographic materials, especially color negative photographic materials, contain not only imaging couplers that serve merely as sources of imaging dyes but also image modifying couplers that after coupling with oxidized developer release a photographically useful group (PUG). Image modifying couplers that release an inhibitor group are referred to as DIR (Development Inhibitor Releasing) couplers. If the inhibitor is linked to the coupler via an intermediate timing group that may or may not serve to delay inhibitor release, it is sometimes referred to as a DIAR (Development Inhibitor Anchimeric Releasing) coupler. The term DIR couplers will be used herein to encompass both DIR and DIAR couplers.
DIR couplers perform one or more useful functions including control of contrast or gamma, sharpness enhancement, granularity reduction and color correction via interlayer interimage effects. The latter function is particularly important in modern color photographic materials. For example, DIR couplers are widely used in the blue-sensitive, yellow dye-forming layers of color negative films, not only for improved sharpness (or acutance) but also to reduce development and dye formation in other layers, especially adjacent green light-sensitive, magenta dye-forming layers. This type of interlayer interimage effect can help correct for unwanted absorptions of the yellow dyes in areas of the negative that contain magenta dyes. It also allows a film to be constructed with higher color contrast while maintaining proper neutral contrast. To date, combinations of yellow image dye-forming couplers and DIR couplers have not provided satisfactory interlayer interimage effects.
There are many references to yellow dye-forming couplers in the art. Among them are U.S. Pat. No. 3,973,968 of Fujihara et al, U.S. Pat. No. 4,022,620 of Okumura et al and U.S. Pat. No. 5,066,574 of Kubota et al, which disclose the synthesis and use of yellow dye-forming couplers with hydantoin derivatives as coupling-off groups and Canadian Patent 1,039,291 which discloses yellow dye-forming couplers with oxazolidine-2,4-dione coupling-off groups. Yellow dye-forming couplers with oxazolidine- 2,4-dione coupling-off groups are also disclosed in GB 1,520,511 and in U.S. Pat. Nos. 4,026,706, 4,203,768, 4,221,860, 4,266,019, 4,286,053, 4,289,847, 4,356,258, 4,370,410, 4,567,135, 4,578,346, 4,622,287, 4,791,050, and 5,100,771. The combination of the particular acylacetanilide yellow-dye forming couplers having oxazolidine-2,4-dione coupling-off groups of the invention together with DIR couplers is not disclosed nor is the unexpected improvement in photographic properties associated with such conjoint usage.
It would be useful to have a photographic element in which a light sensitive silver halide emulsion layer containing a yellow image dye-forming coupler and having a development inhibitor releasing coupler associated therewith would exhibit superior interimage effects.